Demand for bandwidth by enterprises and individual consumers continues to experience exponential growth. To meet this demand efficiently and economically, data centers have to achieve ultra-high density cabling with low loss budgets. Fiber optics have become the standard cabling medium used by data centers to meet the growing needs for data volume and transmission speeds.
Individual optical fibers are extremely small. For example, even with protective coatings, optical fibers may be only about 250 microns in diameter (only about 4 times the diameter of a human hair). As such, hundreds of fibers can be installed in cables that will take up relatively little space. For connections between cables, however, the fibers are terminated with connectors. Multiple fibers may be arranged within a single connector. For example, multi-fiber connectors such as those using multi-fiber push-on/pull-off (MPO) technology may contain and connect 12 or 24 fibers. Connectors, such as MPO type connectors, generally include a housing portion that contains a ferrule that terminates the ends of the fibers. Ferrules are generally used to retain the ends of the optical fibers for connecting the optical fibers. One type of optical ferrule that may be used with MPO type connectors is an MT (Mechanically Transferable) ferrule.
Typically, MPO connectors are joined together to connect the optical transmission path of one fiber optic cable to another fiber optic cable or device, and the connection may be made by inserting the MPO connectors in an MPO adapter. An adapter generally includes a housing, or portion of a housing, having at least one port which is configured to receive and hold a connector to facilitate the optical connection of the connector ferrule with the ferrule of another connector or other device. Adapters may be used to facilitate connections contained within a chassis. The term “chassis” as used herein broadly refers to a containment structure for housing electrical components or switching components.
Ferrules, disposed within the connector housings, get pushed together within the adapter to optically connect the ferrules by means of a so-called PC (Physical Contact) connection, wherein the optical fibers in one ferrule contact the optical fibers in the other ferrule and get compressed together to provide an optical connection. Optical transmission performance between the optical fibers is strongly dependent on connecting conditions such as axis alignment and inclination of the optical fibers, and gaps between the opposing optical fibers.
Any slight misalignment or incorrect inclination of ferrules may degrade the quality of the signal being transmitted. In a chassis-type system, for example, wherein the adapter is mounted to a surface, a plugged-in connector of the adapter may be accidentally bumped or displaced, thereby causing movement of the ferrule of the displaced connector relative to the adapter and/or the ferrule of another connector mounted thereto.
Such a sideways force, or side-loading, on an MPO connector that is mated with another MPO connector generally results in an increase in Insertion Loss (attenuation) of the power as the signal being carried exits one MPO connector and enters the mated MPO connector. Side loading may result in a microscopic separation between the contacting surfaces of mated MPO ferrules, and such a separation creates an air gap between the otherwise contacting end surfaces of the mated ferrules. Any amount of air present between the contacting surfaces of optical connectors may act as a restriction to the light wave passage and, although not a total loss in transmission, may result in fractional power loss. It is desirable to eliminate any power losses present in any fiber optic network.
Therefore, in order to reduce or eliminate potential power loss within an adapter, there remains a need for minimizing movement of connector ferrules after installation in an adapter.